[clang] Minor fix to libASTMatcherTutorial
There was a small error in the code in the tutorial. The tutorial contains a few errors which results in code not being able to compile.
One error was described here: https://llvm.org/bugs/show_bug.cgi?id=25583 .
I found and fixed the error and one additional error.
Reviewers: aaron.ballman, malcolm.parsons
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28180
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@290766
91177308-0d34-0410-b5e6-
96231b3b80d8